Concerns about my father and my child (TW - sexual abuse) - an untrustworthy grandparent

This is a throwaway. I'd really like some advice, reassurance and some female perspective.My wife and I are expecting a little girl in May and we are so happy, and so are all the grandparents.I am concerned about issues surrounding my father and the child, even though these issues may not be true.Four years ago, both his brother and sister (my aunt and uncle) accused my father of sexual assault when they were in their teens. My father denies it totally, and my sister and I (and my mother) believe my father. Well, I think I do, but enough to leave him alone with my future children?Both my aunt and uncle accuse him, but they both have a history of drug abuse, lying and low key mental health issues. They say it happened at a time when my father was dating my mother also.Both my sister and I agree that we were never sexually abused at all growing up, I feel I have very strong memories of my childhood. But I do remember my parents were always openly sexual and I have memories from my childhood that looking back equates to a swinging lifestyle. We were always haphazardly shuffled away.More recently, fixing my fathers computer, I have come across some rather unsavoury pornography, not child or minor related, that shocked me.I guess I'm looking for some guidance on how to bring up children around a grandparent that you don't completely trust.The good news is that he is domestically incapable of looking after himself and cannot make toast or use a microwave. No disability, just a pampered male chauvinist. So he is way down te babysitting list for that reason anyway. via /r/Parenting http://ift.tt/2iLTYlk